SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b33cfbd8f211f393b08ebd4567a713433c252e5cb16734c0796742cfd5f4cdb' 
  AND token = 'OMkiRMzSbjolXkRGMIStxj+spKwmOnoJDotWi+OzqrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}